Over a minimum of 10 years, T-Mobile will maintain its communications facilities on the towers and will have the right, subject to certain limitations, to make modernization changes on the sites. The urban-focused Crown Castle said that 83 percent of the towers are in the top 100 U.S. markets and 72 percent are in the top 50 markets.

Crown Castle owns or control approximately 30,000 towers in the U.S. eclipsing rival American Tower’s stateside holdings by approximately 36%. Boston-based American Tower Corporation operates a combined 30,000 sites in the United States, Mexico, Brazil and India.

Because they primarily act as landlords, consolidation of wireless carriers is generally bad news for tower owners, but the growth of 4G and wireless demand is expected to keep the business thriving.

Crown Castle said it expects the towers to generate about $125 million to $130 million in adjusted funds from operations before financing costs in 2013. Tower buyers expect to pay as much 12 times or more the unit’s cash flow.